The theme for this week's I Heart Faces photography photo challenge is "Smiles." For some, it's perfectly natural to cheerfully say, "Cheese!" when the camera is on them. To others, not so much. Luckily for me, my son falls into the first category. He's always super-duper happy, especially when he's playing peek-a-boo in his trap door of his outdoor castle.

Click on the button below to see many more smiles or visit the I Heart Faces Web site.